Centrifugal pump.



E. THOMSON. CENTRIFUGAL PUMP. APPLICATION FILED NOV. 17,1913.

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m 4 w faw n A TE El STTES ATET ELIHU THOMSON, OF LYNN, MASSACHUSETTS,ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CENTRIFUGAL PUMP.

Specification of Letters Patent.

Patented Nov. 24, 1914.

Application filed November 17, 1913. Serial No. 801,390.

To all whom it may concern:

Be it known that I, Emrm Tuomson, a citizen of the United States,residing at Lynn, county of Essex, State of Massachusetts, have inventedcertain new anduseful Improvements in Centrifugal Pumps, of which thefollowing is a specification.

This invention relates to means for elevating fluids, as water, which isadapted for eneral use, but more particularly where it Is desired toraise the fluid to a considerable height and has for its object toprovide a simple and eflicient structure for this purose. p In carryingout my invention 1 utilize the well known principle of the hydraulic ramin a new and efficient manner.

My invention comprises essentially an endless conduit which may take theform of a closed loop, a ump mechanism of any approved type or causing acirculation of fluid through the conduit, means for checle ing the flowthrough the conduit, and suitable inlet and outlet pipes.

The pump the piston type or the centrifugal type. When of the formertype my invention avoids the use of tight packings and when of thelatter, of hi h pressure series stages.

The principle 0 my invention, together with the novel features thereof,is fully explained in the following specification wherein l havedescribed certain forms which my invention may take.

In the drawing Figure 1 shows a simple form of apparatus in connectionwith a pump mechanism of the piston type and illustrating the principleupon which my invention operates; Fig. 2 shows a preferred form of myinvention wherein a centrifugal pump is used. Fig. 3 illustrates amodification, and Fig. 4 is a section through the rotary valve shown inFig. 3.

Referring first to Fig. 1, the numeral 1 indicates a cylinder withinwhich reciprocates the piston 2 which may be operated by the piston rod3 in any desired manner as by hand or by a suitably connected motor.Communicating with opposite ends of the cylinder, preferably through theto and bottom thereof, is the endless con uit 4 shown in the form of aloop and forming with the cylinder 1 an endless passage for the flow ofthe fluid to be elevated. The

mechanism may be of eitheropenings into the cylinder 1 are provided withsoft washers 6 and 6' forming valve seats against which the piston atthe extreme ends of its stroke rests and with which it coiiperates toform a valve for stopping the flow through the conduit. 7 represents asuitable supply of fluid which might be a tank, pond, or well forinstance, and from which leads an inlet conduit 8. In the presentinstance the pump is shown as being of the double acting type and theinlet pipe 8 is accordingly shown as communicating with the conduit atat points 9 and 10 located on opposite sides of the cylinder and inadvance of which points and in the pipe 8 are seated inwardly openingcheck valves 11 and 12. Communicating with the cylinder 1 is the outletipe 13 within which is seated the outwar ly opening check valve 14 andcommunicating with which is an air chamber 15 as is usualin pumpingsystems generally.

The operation of the arrangement shown in Fig. 1 is as follows: Assumingthe parts to be in the position shown with the piston 2 at the bottom ofits stroke and resting on valve seat 6. It now the piston be movedupward the fluid column in conduit 4 will be set in circulation. Thiswill continue until the piston reaches the top of its stroke when theseating of the same on valve seat (5' will check further flow throughthe con duit. This sudden checking of the flow will cause a building upof pressure in the cylinder beneath the piston due to the inertia of thefluid column in the pipe 4 and will as a result force the fluid outthrough the pipe 13. By this means the fluid can be elevated to aconsiderable height as is well understood in connection with theoperation of the ordinary hydraulic ram. The valve 14 acts as a checkvalve to prevent flow from the conduit 13 back to the cylinder 1. Uponthe upward stroke of the piston, as just described, the fluid forced outthrough pipe 13 will be replaced by fluid sucked in through conduit 8and inlet 10, while on the reverse stroke the fluid will be replacedthrough conduit 8 and inlet 9. By this arrangement I avoid entirely theuse of packings for the piston as obviously the same need not fittightly in its cylinder.

In Fig. 2 I have shown a preferred embodiment of my invention. In thisarrangement the flow of fluid through the conduit 4 means through shaftis produced by the centrifugal impeller 16 which may be operated by anysuitable l7 andpulley wheel 18. Adjacent the impeller and inadvance ofthe same as regards the flow through the conduit 4, is the inlet pipe 19in whichis a check valve 20. Beyond this inlet pipe is located theoutlet pipe 21. havingthe check a which the valve 24: seats to check theflow.

valve Between the inlet and outlet pipe openings is located a valve seat23 upon of fluid through the conduit 4:. The seating of valve 24: uponits seat 23 performs the same function as the seatingof piston 2 uponvalve seat 6 or 6 explained in connection with Fig. 1. The valve 24 isnor- .mally'unseated and might be forced to its seat periodically invarious ways in order to check the flow through the conduit in theoperation of my mechanism. In the present instance it have shown thesame as being held open by a coiled spring 25 surrounding the valve stem26 and playing between shoulder 27 on the conduit 4; and an adjustablenut 28 carried by the stem 26. Con nected to the end of the valve stem26 is one end of a lever 29 fulcrumed between its ends at 3.0 and havingits opposite end connected to stem 31 of a piston 32. The piston 32moves in a cylinder 33 and is responsive to the flow of fluid throughthe conduit 4:.

As a means for accomplishing this I connect the cylinder 33 to conduit4: at a point adj acent a bend therein so that as the fluid flows aroundthe bend a portion will be tangentially deflected against the piston 32and build up a pressure thereagainst which will be proportional to thesquare of the rate of flow. As soon as the pressure on the pistonbecomes sufliciently great it will overcome the opposition of spring 25and begin to seat the valve 24:. As the valve moves toward its seat itwill begin to check the flow through conduit t. Due to the inertia ofthe-moving volume this checking of the flow will begin to build up thepressure behind. the valve and also on the piston and cause the valve tomove quickly and firmly on to its seat. The seating of the valve 2%completely checks the flow through conduit 4 and the pressure resultingcauses fluid to be forced out through pipe 21 as will be readilyunderstood. As soon as the pressure drops again spring 25 will unseatpiston 24: permitting once more the flow of fluid through the conduit4:. In order to more quickly seat the valve 24, ll provide a lost motionconnection between the stem 31 and the end of lever 29. Tbispermits thevalve 24: to be forced to its seat independently of the piston 32 aftersuch piston has moved the valve 2d a strig distance of its seat, thecolumn of centrifugal pump with its simplicity a d ease of operation,and at the same time avoids the use of high pressure stages. Thisarrangement is. further very desirable in that it is entirely automaticin operation.

The form of the invention illustrated in Figs. 3 and at is thesame asthat shown in Fig. 2 with theexcept'ion that in place of theautomatically operated valve 24: T provide a positively actuated valveas shown at 33. This valve 33 is here illustrated as being of the rotarytype and comprises a cylindrical shell opening at one end to theimpeller and having a cut-away portion 34 inthe side. By the revolvingof this cylinder the flow of fluid through conduit 4 is regularlypermitted and checked. As a means of operating the valve 33 a suitablemotor 35' suitably connected as through gearing 36 may be used. Thismotor may be the same as that used to operate the centrifugal pump or itn'iay be a separate motor as found most convenient or desirable.

fWhile l have shown specific forms of valves and operating means inFigs. 2 and 3 it is to be understood that this is only by way ofillustration and that any suitable design of valve and operating meansmay be used and that the-valves of Figs. 2 and 3 may be eitherautomatically or positively actuated. With the arrangement of the inletand outlet openings as shown in Figs. 2 and 3, it will be noted that thepressure created -by the pump is added to that due to inertia of thefluid column during each cycle of operation.

with the apparatus which ll now consider to represent the bestembodiment thereof; but

I desire to have it understood that the apparatus shown is onlyillustrative, and that the invention can be carried out by other means.

What ll claim as new and desire to secure by Letters Patent of theUnited States, is

1. -Means for elevating a fluid comprising an endless conduit for thecirculation of fluid,an impeller for causing fluid to circulate in saidconduit, means for chec v p is u the flow throughsaid conduit, an outletpipe communicating with saidconduit, and an outwardly opening checkvalvein said outletpipe. v 2. Means for elevating a fluid comprising aconduit in the form of a closed loop, an impeller for causing fluid tocirculate around said loop, means for ehecg the circulationan outletpipe connected with a conduit in the form of a close the loop, and anoutwardly opening check valve in said outlet pipe.

3. Means for elevating a fluid com rilsing, p, means for causing fluidto circulate around said loop, a valve in the loop for checking saidcirculation, an outlet pipe communicating with the loop, an outwardlyopening check valve in said outlet pipe, an inlet pipe communicatingwith said loop, and an inwardly opening check valve in said inlet pipe.

4. Means for elevating a fluid comprising a conduit in the form of aclosed loop, means for causing fluid to circulate around said loop, avalve in the loop for checking said circulation, an outlet pipecommunicating with the loop, an outwardly opening check valve in saidoutlet pipe, an inlet pipe communicating with said loop, an inwardlyopening check valve in said inlet pipe, and means for periodicallyoperating said first named valve.

5. Means for elevating a fluid comprising a conduit in the form of aclosed loop,

means for causing fluid to circulate around said loop, a valve in theloop for checking said circulation, an outlet pipe communicating withthe loop, an outwardly opening check valve in said outlet pipe, an inletpipe communicating with said loop, an inwardly opening check valve insaid inlet pipe, and means controlled by the rate of flow of fluid inthe loop for operating said first named valve.

6. Means for elevating a fluid comprising a conduit in the form of aclosed loop, an impeller located in the conduit, means for operating thesame, an inlet pipe adjacent the impeller, an inwardly opening checkvalve therein, an outlet pipe adjacent the inlet pipe, an outwardlyopening check valve in said outlet pipe, a valve for closing theconduit, and means for operating said valve.

7. In an apparatus of the character described, the combination of acentrifugal pump, a conduit connecting the delivery side thereof to thesuction side, a discharge pipe connected with the conduit, an outwardlyopening check valve therein, a valve in the conduit between thedischarge pipe,

and the suction side of the pump, and means for operating said lastnamed valve.

In witness whereof, I have hereunto set myahand this twelfth day ofNovember, 191 l ELIHU THOMSON.

Witnesses:

Joan A. MCMANUS, Jr., ALEX. F. MACDONALD.

